January 04, 2005
Trimtab

I ran across this term today (also written as two words, trim tab) and didn't know what it meant. Here's what I found...

An image first used by Buckminster Fuller (and explored in Harold Willen’s 1984 book The Trimtab Factor) is the trim tab on a rudder. To change the direction of a really large ship or airplane, we need a really large rudder, too large a rudder, in fact. The power of the currents of air or water, combined with the size of the rudder, make it almost impossible to move the rudder without breaking it. The solution is to put a tiny rudder, called a trim tab, on the larger rudder. The trim tab moves easily because it’s small. But as it moves, it causes the currents to shift, which makes it easier for the large rudder to move, which in turn makes the even larger ship (or plane) change course. The physical mass of the trim tab is a tiny fraction of the weight of the ship or plane, yet the trim tab determines the vehicle’s course.

The American Revolution illustrates the trim tab effect. The revolution didn’t happen because the majority wanted it. In the early 1770s, only a handful of radical intellectual were thinking the unthinkable of breaking with the biggest naval power on the planet. Even by 1776, support for independence was by no means unanimous or even the majority. Strong elements within the middle and southern colonies wanted to keep the economic and military protection of Britain. Loyalists to the Crown were everywhere. It’s estimated that only 11 percent of the population were actively involved in making the American Revolution happen.

Posted by Dave at January 04, 2005 11:58 AM